Migrating people gradually dominate this region: Sarmatians, Goths, Huns, Gepids and Slavs.
Dacian settlements and fortifications were developed throughout the county. The most important ones have been researched archeologically: Săvârșin, Vărădia de Mureș, Cladova, Clit, Berindia and Pecica (identified with Ziridava, which was mentioned by Ptolemeu)
The first Romanian voivodships were developed around some groundfortresses such as those discovered at Vladimirescu, Cladova, Zărand.
The first mention of Arad county as part of the Hungarian kingdom.
Devastating Tatar Invasion
The stone fortresses Șoimoș, Șiria und Dezna were built.
The dominance of the Ottoman Empire was installed. The Turks organised the territory in three sanjaks with the centers in Arad, Lipova and Ineu.
The Peace from Karlowitz - Following the victory of the Austrians in the battles with the Turks, the Mureș river became the border between the Austrian Empire and the Ottoman Empire. The Banat region remained under Turkish domination up until Lipova. The Austrians organized border regiments consisting of Serbians, Romanians and Hungarians.
Arad became a chamber city, which provided certain economical advantages. The first guild was recorded.
The Peace from Passarowitz - the Austrian rule extends over to the Banat. The Mureș looses its importance as a border between the empires.
German colonists are being brough South of the Mureș;
Arad county is included in the Austrian Empire. Vast damming and improvement works are being started alongside the Mureș river.
The border regiments are being dissolved, some of the Serbs move to Russia; Arad becomes the center of the new noble countship.
The Fortress of Arad was built inside of the Mureș loop after the designs of Ferdinand Philipp Harsch,
Arad becomes a free royal city.
The European Revolution divides the population of the county. The Romanians take part at the meetings from Blaj and enrole in Avram Iancu's army. The Hungarians fight against the Austrian troops from inside of the fortress, who bombed the city for 9 months. The Hungarian revolutionary army surrenders at Șiria, while 500 officers are incarcerated inside of the fortress of Arad. 13 of the generals are convicted to death and executed under the fortress walls.
The dual austrian-hungarian Regime was installed.
Arad is the centre of Unionist Movement. The Central Romanian National Council is here active.
Arad alongside the whole region of Transylvania is united with Romania.
The Romanian administration was installed.
The county of Arad is the fourth economical center of Romania.
The pupils of the subcommander school of Radna stop the advancement of the german troops.
The Communist state takes over all companies. The county maintains its frontline position for the national economy due to the massive investments.
The population of Arad joined the revolutionaries in their movement against the regime.